kfsu, egypt

1st SMARTEX-Egypt 2011(World Textiles Conference), Nov, 22-24 2011, Kafrelsheikh University, Egypt

Faculty of Specific Education

KFSU, EGYPT


FITTING STRETCH MODEL OF THRE E-DIMENSIONAL FOR SIMULATING APPAREL SURFACES


FITTING STRETCH MODEL OF THREEDIMENSIONAL FOR SIMULATING APPAREL SURFACES

ELSAYED A. ELNASHAR, VICTOR KUZMICHEV & N. A.SAKHAROVA Faculty of Specific Education, Kafrelsheikh University, Egypt. & Ivanovo State Textile Academy, Russia.

[email protected] Cell Phone : +2 0106 92 88 940

Background The first decade of the 21st century brought about a revolution in anthropometry. For garments the phases of product devel opment and preparation of production require approximately triple the time of the actual garment life span. The developm ent of existing technology made it possible to collect anthrop ometric data using a non-contact body scanner. In order to c ompensate for resulting grater efforts in the product preparat ion and to react more quickly and flexibly to the latest fashio n, the technology. Clothing manufacture is extremely labourintensive. At present, there are various software tools for 2D design, grading, nesting and so on, allowing great saving of time and material; however, each of them covers only a parti cular step of the garment design process.


There is a strong request of integrated systems for the whole process including the possibility for the designer to work directly in a 3D environment. 3D technologies haven't had wide practical application yet, despite the conclusive advantages of virtual design to traditional 2D pattern making. More important reason which limited the distribution of virtual technologies is absent the way how to reproduce the pleated real surfaces of single and multilayered virtual clothes. Nowadays 3D technologies represent the system “body-clothes” in two variants:


“skinny” shapes with ideally smooth surfaces located (1 around the human body skirt (based on the Chebishev’s theory). Such method of clothes shaping is used, for example, for underwear design;

2) loose shapes having the air gaps located between the human body and the clothes on the anthropometric levels. By means of the air gaps the single-layer clothes as much as possible may be shaped around the human body.

This research goal is This paper solves the simulating fitting stretch surface on volume body (of three-dimensional apparel surfaces), using an innovative method. First, we use a triangular mesh to represent a surface. Then a unified stretch theory a based model is established to flatten a 2D surface into a 3D pattern. The accuracy of any local area of the surface can be easily controlled in the process of development. We use an interpolation function to show the unified stretch theory distribution of developed surface. Including the algorithm to reduce error for the resulting developed surface. Our method can efficiently develop a complex trimmed surface, which is usually quite difficult to be developed by earlier methods.


(1) the block pattern, (2) the human body, and (3) the clothes shapes made from the pat terns and have put on the body. Really practicing designers have such knowledge ho w to fit the patterns on the body, and the problem is how to formalize it ideas for c omputer design. New up-to-data information should connect the sizes of the different areas of clothes by equations, for example, on the waist, bust, hip levels, if one of the m is changed [7].

To increase the realness of interaction between the human body and the clothes it’s necessary to use the mathematical description which includes the textile materials properties. However it is not enough to get the realistic shape of virtual clothes. In our opinion, to improve the 3D clothes virtual design is important to formalize all relationships that consist between the similar parts of three independent objects:

The whole garment is constructed from four parts: the collar, • the coat, the sleeves and the trousers (or skirt) [9]. A basic technique in any of these areas is the approximation of a desired surface with a given surface such as ancient Egyptian. The systems designed to acquire the motion of points on a flexible-moving surface such as cloth. Historical research has uncovered ancient Egyptian formulae for many conditions of which the aesthetical of stretch fabric, the reduction of stretch wrinkling, and there were in circulation at that time recipes for facilitating hair growth and getting rid of stretch clothes , the dressed of stretch fabric used as the following picture in figure 1.

3-D energy cloth stretch dress at sculpture

Figure 1: Illustration of 3-D energy cloth stretch dress at sculpture. "a, b, and c""Egyptian art"[1,4].

• The unified stretch theory, adopt unified theory of stretch on the potential of interior fabrics resulting from the stretch raw material and fabric structure "which attract inward", and their relationship to the outside of the energy severity "stretch fabrics" resulting from body size, three-dimensional effect and aesthetical durability. The exiting approaches can generally be classified into three categories: geometric, physical, and hybrid technologies, geometric methods apply geometrical of stretch clothes coefficient (SCC). In this work, stretch clothes coefficient was defined as the ratio of the volume of clothes when it is stretched with the full geometrical volume of the clothes form, expressed as percentage. [9]

Stretch distance coefficient (SDC): When clothes are stretched freely with its only support at bearing area is located between shoulders and chest level for each kind of dresses, the appearance of the clothes depends on numerous factors such as fabric type and construction features. The process of converting the processed image of a dress into a modified form of the polygonal model that is used to calculate stretched distance coefficient.

2. IMPLEMENTATION V-Stitcher™ is the most powerful 3D design and visualization software accelerating the entire product development life-cycle; t interfaces seamlessly with AccuMark pattern design, grading and marker making software, enabling a fast and easy transformation of 2D patterns into 3D garments. V-Stitcher is a key component of Gerber’s Product Lifecycle Management (PLM) offering; which significantly reduces product development costs and improves time-to-market through the creation of virtual garment samples. Using 3D simulation to test multiple print variations; allowing you to make important design decisions before a physical sample is produced; saving both time and money.

- Real-time

fit approval sessions can be held online, across the globe. 3D notes, and the ability to save and embed the 3D files allows for maximum flexibility when creating tech packs. -Virtual samples reduce the need to exchange physical samples through the mail, saving time and costs. - 3D samples enable faster detection of errors and earlier corrections Eliminates the distance between stakeholders.

3. MATERIAL AND METHODS

• Fabrics generally show nonlinear response in bending. Their nonlinear moment-curvature response is often measured by the Kawabata bending test system [5]. One fabric used in this study was a twill-weave, 100-percent cotton fabric. It had the following physical properties: In this software program the bending properties in warp and weft, direction, the tensile properties in warp, weft, 45-degree warp and 135 degree direction and also the weight per unit are considered in the draping module. The scale of the property curves depends on the measurement devices.

4. RESULT AND DISCUSSION During the developing process, the area of the surface may change. The final relative area difference element method and Patterns developed in AccuMark are used to create the virtual samples in V-Stitcher. Only Gerber Technology offers a direct interface between AccuMark and V-Stitcher, and with easy file sharing there is no need for data conversion.

4.1. 3D SURFACES OF CLOTHES In our opinion the weakest position of modern 3D CAD design is ignorance the clothes patterns influencing for the 3D features. To forecast the patterns indexes. In this direction we did some works which include: A new classifications of 3D clothes shapes based on the usual features of shape (such as closely fitting, loosely fitting, semi closely fitting, etc), on one hand, and the air gapes in system “body - clothes”, on other hand. This classification allows to connect the 3D shape and 2D patterns and to predict the clothes shaping. As example you can see the fragment of such classification that we created for women clothes.

4.2. MEASUREMENT PROTOCOL Three trained anthropometrists measured and recorded each dimension three times using a tape measure to the nearest sixteenth of an to minimize error, one anthropometrist measured while the other dimension was deemed as the physical measurement for that dimension. The potential fields for application in particular in mechanical engineering and Pattern construction under consideration of the material behavior, if curved element contours of lightweight textile structures are covered with an undefined shape of the reinforcing textile, the mechanical component properties may deteriorate, the patterns should be developed directly on the object to apply the reinforcing structures to the desired 3D shape according to the required load and thus avoiding rework. Creation the equations for describing the wrinkles that appeared on the shell surface from textile materials.

The research is directed on working out of methodology of new design of clothes in system “CAD + 3D body scanner”. Two new databases are put in a basis of this methodology: - the first one includes the schedule of indexes about the patterns (2D), collected from second half ХХ–ХХI;

- the second one includes the quantity information about the outline clothes shapes (3D) of the same period, digitized by the body scanner. (1) The new technology that connecting the flat patterns (front, back, sleeve), on one hand, and the outline shapes of systems “body-clothes”, on other hand, is developed for main kinds of outer clothes (jackets, coats, dresses, trousers, skirt).


-Curves can be created by the grid method at each block of a semi-fit silhouette and loose-fit silhouette. The grid method is the way to divide the width and height of a block by the number of a row and column and to arrange the curves on the piece. Since flattening is made by using the length of a segment of a triangle, curves were created at each grid diagonally.


Using 3D curves, we manufactured 2D triangles we also made grids by connecting two triangles, arranged each grid to keep the length of the outer curve and calculated the surface flattening piece of each block. This surface flattening piece is called an apparel pattern consisting of each silhouette (fig. 2). Then we can see fitting equation is the Chest circumference () of stretch distance coefficient as follows:

Where: Y = maximum distance of node from the edge of the waistline contour, Where: Y = minimum distance of node from the edge of the waistline contour, n = number of nodes.


Figure 2. Topological fitting clothes of frame of 3D system “women body – jacket and skirt” for putting on the surface from textile materials


Then we can see fitting equation is the Bust circumference () of stretch distance coefficient as follows:





4.3 CLOTH OF SKIRT

Skirt has its private rule knowledge and processing course. The rule knowledge includes the rules inferring the values of some parameters of the key points from the style description and the cacuprodedure includes the procedure for calculating the values of some parameters of the key points. With the class hierarchy of garment style, the procedure of the illation mechanism is as follows: first, the design interface receives the semantic description of the clothing style, then the illation mechanism searches the corresponding cloth stretch in apparel surfaces of different garment parts, and the 3D clothing style cloth stretch in apparel surfaces is displayed. If the user is not satisfied with the 3D style effect, he can change the 3D shape of the style both by changing the style description and the value of the numeric variables.


The most complex part of the body to be covered by garment is usually the bodice, of which the shapes differ from person to person and the surface curvature variations are large. Therefore, the automatic generation of bodice pattern was focused in this study, as it is very difficult to design accurate bodice patterns by flat pattern processes only.








Skirt surface of stretch cloths has forces stem from deformation: deformations store some potential of stretch energy, Stretch/Shear/Bending, derivative of potential of stretch energy = force, Skirt surface of stretch cloths has the potential of stretch energy functions for each type of deformation is: Fitting the front part of skirt () by using the following equation



In additions, Comfort skirt surface of stretch cloths is related to how the clothes feel against the body when the individual is wearing it. Some skirt surface of stretch cloths is not meant to be comfortable while other clothes are focused on this issue. Comfort for most clothes s is related to everyday actions that must be done when wearing skirt surface of stretch cloths such as sitting, bending, walking, and reaching. These actions must be performed in the clothes without straining the clothes and/or seams or feeling compressed or restricted. In additions, Comfort skirt surface of stretch cloths is related to how the clothes feel against the body when the individual is wearing it. Some skirt surface of stretch cloths is not meant to be comfortable while other clothes are focused on this issue. Comfort for most clothes s is related to everyday actions that must be done when wearing skirt surface of stretch cloths such as sitting, bending, walking, and reaching. These actions must be performed in the clothes without straining the clothes and/or seams or feeling compressed or restricted.


6. CONCLUSION

In order to improve the fashion design efficiency and make it possible for the common user to design professionally, we developed researches on fashion intelligent design system. As the process of fashion design is a creative thought process, and the garment is a kind of flexible objects, it is a hard work to express and digitize the knowledge of design. In this paper we constructed the 3D of woven stretch cloth of a garment with basic concepts curves surface patches, established the relations between the garment styles and the parameters of 3D garment of woven stretch cloth.


By setting up the knowledge base with object-oriented technology and illation mechanism, we accomplished the 3D garment intelligent design. The finite-element approaches show significant promise in the area of fabric motion simulation due to its inherent geniality in dealing with arbitrary shapes, materials, loads, and contact surfaces. Future work must be directed at developing algorithms that promote faster solution times. Current solution times are excessive for use in complex "real-world" garments.


Thanks